TCFP Plans Examiner Practice Test

During a main drain test, what must be recorded first?

1. Pressure drop

2. Pressure on system side

3. Final static pressure

4. Open main drain

The correct answer is: Pressure on system side

Recording the pressure on the system side is critical during a main drain test because it establishes the baseline conditions of the system before any alterations are made. This initial measurement is essential for accurately assessing the system's performance and verifying that it meets the required specifications. It provides vital information about how the system operates under normal conditions, which is crucial for comparing against the results obtained during the test. The subsequent measurements, such as the pressure drop and final static pressure, depend on this initial reading to determine how effectively the system maintains pressure and functionality when the main drain is opened. By starting with the pressure on the system side, you ensure that all future comparisons and analyses are grounded in a precise understanding of the system's state prior to testing. This methodical approach plays a key role in evaluating the overall health and efficiency of the firefighting system in question.